Water aeration apparatus

ABSTRACT

A water aeration apparatus is used for aeration purposes in the water-filled areas such as dams, impounded water or reservoirs, and lakes and marshes, and includes a tubular casing and supply chamber that causes large quantities of water to be exposed to the flotation action of air supplied under pressure, thus raising the water up to the surface. The apparatus may be used for water purification, or for anti-freezing purposes particularly in cold climate regions. The apparatus includes a collective tubular casing and a multiple-partitioned or common air supply chamber below the casing, the tubular casing including a plurality of tubular air and water passages formed by dividing the interior of the casing into several longitudinal passages or by combining individual tubes together.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a water aeration apparatus, moreparticularly to an aeration apparatus which takes advantage of theraising, flotation or suction action of air under pressure for causing alarge amount of water to be exposed to that action for aeration purposesor water purification as well as anti-freezing purposes in water-filledareas such as dams, impounded water or reservoirs, and lakes andmarshes.

2. Description of the Prior Art

A conventional water aeration apparatus of the type using the raising orsuction action of air supplied under pressure to the water has been usedfor aeration purposes in dams, impounded water, reservoir installationsor natural water resources such as lakes and marshes, and is known toprovide an effective means for that purpose (as disclosed in theJapanese Utility Model Official Publication as opened to the publicexamination under No. 57 (1982)-39117).

The conventional apparatus includes a tubular casing, which has a singlepassage through which water is pumped upwardly by its exposure to theaction of air supplied under pressure, and the passage has a borediameter range of 40 cm to 50 cm. Because of the single water passageconstruction, the single tubular casing has limitations in its capacityfor handling water at a time. When this apparatus is used in a daminstallation or elsewhere which contains water to a depth of for example20 m or more, each tubular casing is required to be installed for onemillion volumetric tons of water to be handled. Therefore, it isnecessary to increase the number of the individual tubular casinginstallations as the volume of water to be handled increases.

It should readily be understood from the above that for a single passagetubular casing, ten tubular casing installations are required forhandling ten million volumetric tons of water, and one hundredinstallations are required for one hundred million tons of water, whichcan easily be found from a simple calculation. A corresponding number ofadditional installations are required for additional tons of water.Increasing the number of individual tubular casing installations resultsin additional pieces of accompanying equipment such as air supply hoses,air compressors, and motors, in addition to which require regular oroccasional maintenance service. This raises a problem to be solved. Asone solution, it may be suggested that the number of individual tubularcasing installations be reduced by increasing the transverse crosssection or bore diameter of a single tubular casing. Increasing thediameter, however, leads to a considerable increase in the volumetriccapacity of an air chamber which is located below the tubular casing.The volume of such air chamber may be found from the following equation,for example:

    V=k(4/3)πr.sup.3

where k is a factor of 0.3 to 1.0, r is a radius of a tubular casing,and V is the volume of an air chamber.

It can be seen from the above equation that the volume of the airchamber increases in proportion to the cube of the radius of the tubularcasing. Thus, increasing the diameter for the tubular casing poses aproblem since it requires a larger air supply. This is undesirable fromthe energy saving needs.

SUMMARY OF THE INVENTION

In order to solve the problems mentioned above, it is therefore oneobject of the present invention to offer a single tubular casingconstruction that includes a number of smaller diameter tubular passagesrequired to provide a total diametrical cross section as indicated inthe above equation.

Specifically, in its one form, the collective tubular casing accordingto the present invention comprises a number of individual tubes or pipes(for example, two to ten) having a smaller bore diameter (such as 30 cmto 50 cm, for example), and below those tubes a multiple-partitioned airchamber for each of the tubes or a common air chamber for all the tubes.Thus, the single tubular casing, which is installed at one site, canhandle more water to be pumped up for the aeration purpose. In anothervariation, a large bore-diameter tubular casing may be dividedinternally to provide a plurality of longitudinal tubular passages.

BRIEF DESCRIPTION OF THE DRAWINGS

Those and other objects and features of the present invention willbecome apparent from the detailed description of several preferredembodiments that follows with reference to the accompanying drawings, inwhich:

FIG. 1 is a front elevation of one form of the collective tubular casingembodying the present invention, which is constructed from individualtubes or pipes;

FIG. 2 is a plan view of the construction shown in FIG. 1;

FIGS. 3 through 10 illustrate the different configurations as seen fromthe plan view, each of which includes a different number of smalldiameter tubes which are arranged differently: specifically, theconfiguration in FIG. 3 includes two tubes, the one in FIG. 4 includesthree tubes arranged in a triangular form, the one in FIG. 5 includesfive tubes arranged in a pentagonal form, the one in FIG. 6 shows thepentagonal arrangment including one center tube and five surroundingtubes, the one in FIG. 7 is configured to include six tubes which inthis case are arranged in a triangular form, the one in FIG. 8 alsoincludes six tubes which are arranged in two rows, FIG. 9 shows theconfiguration which also includes six tubes which are arranged in acircle, and FIG. 10 shows nine tubes arranged in three rows.

FIGS. 11 through 13 are enlarged sectional views illustrating thedifferent constructions of an air chamber for the embodiment shown inFIG. 1;

FIG. 14 is a plan view of another embodiment including a larger diametertubular casing internally divided into three smaller diameterlongitudinal passages of an elliptic cross section;

FIG. 15 is a plan view of still another embodiment including threeindividual small-diameter tubes bound together;

FIG. 16 is a front elevation of a variation of the two precedingembodiments;

FIG. 17 is a plan view of the variation in FIG. 16;

FIG. 18 is an enlarged sectional view of an air chamber for thevariation of FIG. 16; and

FIG. 19 is a front elevation of a variation of the tubular casing inwhich the air chamber is located between the individual tubes and theadditional water suction pipe that extends below the air chamber;

FIG. 20 is a plan view of the variation of FIG. 19; and

FIG. 21 is a plan view illustrating an example of how the tubularcasings are installed at different locations in a sea port or bay.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

First, the embodiment shown in FIGS. 1 through 13 is described indetail. As shown in those figures, this embodiment includes manypossible variations in which water passage tubes may be arranged both indifferent numbers and in different geometrical configurations. FIGS. 1and 2 are a typical, basic example of those variations. Then, thefollowing description is made by referring to the example shown in FIGS.1 and 2. In FIGS. 1 and 2, a collective tubular casing, which isgenerally designated by 2, comprises a collection of smaller borediameter tubes 1, 1a, 1b, 1c having inlets in downstream ends thereofthrough which water is pumped up and outlets in upstream ends thereofunder the action of air supplied under pressure, and an air chamber 3which is located below those tubes and supplies air under pressure. Theair chamber 3 may be partitioned separately for each of the tubes asshown in FIGS. 11 and 12, or may be provided as a common air chamber forall the tubes as shown in FIG. 13. The detailed construction of the airchamber in both cases will be described later. The collective tubularcasing 2 shown in FIGS. 1 and 2 may have many possible variations asshown in FIGS. 3 through 10. In FIG. 3, it is configured to include twotubes, as designated by 4. The variation 5 in FIG. 4 includes threetubes arranged in a triangular form. FIG. 5 shows a variation 6 in whichfive tubes are arranged. In the variation 7 shown in FIG. 6, six tubesare used with one center tube surrounded by the other five tubes. Thevariation 8 in FIG. 7 also uses six tubes, which are arranged in atriangular form. In FIG. 8, six tubes are arranged in variation in tworows to form a collective tubular casing. FIG. 9 shows a variedconfiguration 10, which also includes six tubes arranged in a hexagonalform. Finally, the variation 11 in FIG. 10 includes nine tubes arrangedin a square form. Collectively, those tubes determine the total diameteror area in cross section of a single tubular casing. Therefore, thetotal diameter may be increased by increasing the number of individualtubes, which may be more than nine tubes. For any number of individualtubes to be used, those tubes should be configured geometrically so thatthe collective tubular casing provides equilibrium and positionalstability when it is actually installed deep in water.

In conjunction with the water pumping action of the various forms of thecollective tubular casing described above, the construction of the airchamber which is located beneath the tubular casing is now described. Inits one form, as shown in FIGS. 11 and 12, the air chamber 3 includesseparate air supply compartments, the number of which correponds to thenumber of the individual tubes, i.e. 1, 1a, 1b, 1c, etc. making up thetubular casing and each of which communicates with a corresponding tube.Those air supply compartments are enclosed by an outer jacket 12 whichis equipped with a top end plate 13. The outer jacket 12 is hermeticallymounted around the individual tubes collectively. Each of the air supplycompartments is formed by cylindrical partitions 14 and 15, which areconcentrically spaced apart from each other and inserted between theouter jacket 12 and its corresponding tube. As shown, for example, thecylindrical partition 14 has an air communicating aperture 16 at theupper portion while the partition 15 has an air communication aperture17 at the lower portion. Thus, a gap or air receiving space 22 formedbetween the outer jacket 12 and partition 14, and a gap or air receivingspace 23 formed between the partitions 14 and 15 communicate with eachother through the aperture 16. Similarly, the gap or air receiving space23 and a gap or air receiving space 18 formed between the partition 15and the corresponding tube communicate with each other through theaperture 17. Air communication between the gap or air receiving space 18and the corresponding tube is made through windows or apertures 19, 19b,19c which are made in the tube. Each of the air supply compartments hasan air inlet port, through which, as indicated by an arrow 21, air issupplied under pressure into the outer gap or air receiving space 22from an air supply or suction hose 20, 20b, 20c which connects with anyexternal compressed or pressurized air supply source, such as an aircompressor. The air under pressure passes through the inlet port and isdrawn into the gap or air receiving space 22 and then through theaperture 16 into the gap or air receiving space 23. During the time thatthe air supply continues to take place, the air is gathering upwardlyinside the gaps or air receiving spaces 22 and 23 and the water levelinside these gaps or air receiving space is gradually lowered under theaction of the expanding volume of air.

When the above water level has been lowered down to the broken lines 24where the aperture 17 is located, the air mass filled inside the gaps orair receiving spaces 22 and 23 is siphoned in the direction of an arrow25, since the gap or air receiving space 22 is in fluid communicationwith the water to be circulated at a position lower than the aperture17, which allows the gaps or air receiving spaces 22, 23 and 18 to befilled with water as the air mass is pulled by a siphon effect throughthe gaps or air receiving spaces 22, 23 and 18. The air mass passesthrough the aperture 17 to flow upwardly in the direction of an arrow 26and then through the aperture 19b to flow into the tube as indicated byan arrow 27. The air flow into the tube then forms into a single airmass like a bullet shape 28, and rises upwardly through the tube. As theair mass is rising, the portion of water above the air mass is lifted orboosted, and the portion of water located below the air mass is placedunder the suction action of the air mass and is pumped upwardly. As longas the compressed air continues to be supplied into the air chamber, airmasses are successively formed inside the tube at time intervals (suchas every thirty seconds) and intermittently pass through the tube toeffect a lifting and suction action on the water above and below eachrespective air mass. Thus, portions of water are intermittently raisedat periodic time intervals. In fact, when a given air mass is risingthrough the tube toward the surface, the water flow through the tubeunder the air mass suction is initially being raised at the same speedas the rising speed of the air mass. When the air mass reaches thesurface and appears in the atmosphere above it, the water flow throughthe tube has its inertia action and its rising speed becomes slightlyslower. Thus, this change in the water flow speed causes intermittentjets of water, rather than a constant flow of water, when it is gettingout of the tube. The jets of water produce water rings over the surface,diffusing effectively in radial directions. Thus, a large sphere ofconvection is formed around the collective tubular casing, and watercirculates between the surface and the depth (such as a depth of 30 mand more). This enhances the capability of the single collective tubularcasing, allowing it to handle 10 million tons of water at one site.

FIG. 13 shows a variation of the air chamber 3 in FIGS. 11 and 12, whichprovides a common air chamber for all of the individual tubes 1, 1a, 1band 1c. A single air supply room is provided below the bottom ends ofthose tubes, and communicates with each of the tubes. As shown, the flowof air supplied through the apertures 19b, etc. gathers upwardly in asingle area which has a diameter substantially equal to that of a singletubular casing. Then, the air flow is distributed into each individualtube, rising through it toward the surface and forming an air mass.Thus, water is drawn into the single area under the suction action ofthose air masses, and is also distributed into each tube. Thereafter,the water circulates as described for the air chambers in FIGS. 11 and12.

A varied form of the collective tubular casing described in thepreceding embodiment is shown in FIGS. 16 through 18, which includes anair supply chamber whose construction differs from the preceding ones,and water suction pipes in addition to those tubes described above. Forthe purpose of easy comparison with the preceding embodiment, thecollective tubular casing includes the same number of individual air andwater passage tubes (four), but may include additional tubes. In theembodiment particularly shown in FIG. 16, the collective tubular casing2 includes small-diameter individual tubes combined together, a commonair chamber 31 which is located below the tubes and communicates witheach of the tubes, and water suction pipes 30, 30a, 30b, and 30c each ofwhich is connected with the corresponding tube. As shown particularly inFIG. 18, the air chamber 31 includes an outer jacket 32 closed at thetop, an inner cylindrical partition 33 open at the top and closed at thebottom, and a tubular passage or conduit 34 which extends through theclosed top of the outer jacket 32 and allows air to flow therethroughinto the individual tubes. Those parts 32, 33 and 34 are arrangedconcentrically in spaced relationship with respect to each other.Compressed air is supplied from an air supply or suction hose 35 intothe air chamber 31 as indicated by an arrow 36, and gathers upwardly inthe air chamber 31. As the air supply increases the water level in theair chamber decreases down to the position where the bottom open end ofthe tubular passage 34 is located. This allows the air in the chamber 31to flow by a siphon effect through gaps 38 and 39 and then through thetubular passage 34 as indicated by arrows 40, 41, and 42. After the airpasses through the tubular passage 34, the air flow enters the spacebelow the individual tubes, and is then distributed into each of thetubes, as indicated by an arrow 43. The portion of air in each tubeforms into an air mass like a bullet shape 44, rising through the tubetoward the surface. This causes water to be drawn through the watersuction pipes 30, 30a, 30b, and 30c into each of the tubes due to thesuction of the air masses, as indicated by an arrow 51. Then, as the airmasses continue rising, the portion of water in each tube also risesthrough the tube, as indicated by an arrow 45.

The above described embodiment differs from the preceding embodiment inthat the water suction occurs at several points instead of a singlepoint and the air chamber 31 is constructed accordingly. It should beunderstood, however, that the function provided by the embodiment inFIG. 18 is the same as that in the preceding embodiment.

The air and water passages making up the tubular casing may be varied asshown in FIGS. 14 and 15. In FIG. 14, the interior of a larger-diametertubular casing 46 is equally divided into three separate portions 47which are formed like an arc shape, and three smaller-diameterelliptical shaped tubes 48, 48a, and 48b forming the air and waterpassages are provided longitudinally. In FIG. 15, three smaller-diametertubes 49, 49a, and 49b are bound by ropes 50, forming a collectivetubular casing. In either case, the air chamber as described in thepreceding embodiments may be used.

A further variation of the collective tubular casing shown in FIGS. 19and 20 includes an air chamber that is located between four individualsmall-bore diameter water passage tubes and an additional water suctionpipe that extends below the air chamber. In its specific construction,the air chamber 53 is formed below the lower ends of the individualwater passage tubes 54, 54a, 54b, and 54c so that it can communicatewith each of those tubes for supplying air under pressure, and the watersuction pipe 54 extends below the air chamber, through which water risesunder the suction effect of the rising air supplied from the airchamber. The length of the water suction pipe may be determined,depending upon the depth of the water in which the tubular casing isactually to be installed.

This construction described above is particularly useful in allowingdeep waters, such as dam installations and lakes and marshes, to beaerated. For any lake which is 80 m deep, for example, the constructionthat includes the four tubes of 30 m and the water suction pipe of 20 mlength may be used. This specific construction of tubular casing may beinstalled so that the top ends of the tubes are located at a depth ofabout 5 m to 10 m beneath the water surface, and air may be suppliedunder a low atmospheric pressure equivalent to about 2 atms. Under theseconditions, the portion of water which is located 50 m to 60 m deep caneffectively be subjected to aeration. The fact that air can be suppliedunder such low pressure allows for the use of any low-pressure airsupply equipment. The use of the low-pressure air supply makes the totalsystem including the other accompanying equipment less costly than usingan air supply under high-pressure. This also reduces any difference inthe air volumetric capacity between the air chamber and the upperportions of the individual tubes. As such, the operation can continuesmoothly.

The constructional and operational features of the various forms of thecollective tubular casing according to the present invention have beendescribed, and in order to help better understand those features, atypical example of actual usage of any of those forms is now illustratedby referring to FIG. 19. FIG. 19 shows the example in which severaltubular casings 2 are to be installed at appropriate intervals in a seaport or bay in cold climate regions. When any of those collectivetubular casings is installed, it is placed in its vertical position deepin to the water, with its bottom end located near to the bottom of thewater and its top end located at a depth of about 5 m beneath the watersurface. Then, compressed air is introduced into the air chamber fromany external air supply source such as an air compressor. The airgathers upwardly in the air chamber and then is released from the airchamber, flowing into the individual tubular passages usually in theform of tubes. As the air is rising through each of the tubularpassages, it forms into an air mass like a bullet shape. Following thefirst air mass, another air mass is formed in the same manner asdescribed above. Thus, the portion of water which is sandwiched betweenthe preceding and following air masses is rising through the tubularpassages under both the suction and flotation or boost actions of theair masses. That portion of water located near the bottom of a body ofwater contains less oxygen, is raised or lifted toward the surface, fromwhich it is jetted and diffused in radial directions as indicated by anarrow 52. Then, the portion of water located on the surface andcontaining enough oxygen is in turn being lowered toward the bottomunder the action of the produced convection. Exchanging those portionsof water between the bottom and surface improves the oxygen content inthe water rapidly. This water circulation by convection also provides aneffective anti-freezing means. Since the portion of water located nearthe bottom is usually maintained at a temperature of 4° C. at thelowest, the water at the surface can also be maintained at a temperatureof 4° C. or higher by causing the water to circulate by convectionbetween the bottom and surface.

Although the present invention has been described by way of the severalpreferred embodiments thereof, it should be understood that variouschanges and modifications may be made without departing from the spiritand scope of the invention.

What is claimed is:
 1. A water circulation apparatus comprising:atubular casing having a plurality of tubular passages extending in alongitudinal direction along the entire length of the tubular casing andsaid plurality of tubular passages being open at each end thereof; andmeans for forming large intermittent air masses which pass through saidtubular passages when said tubular casing is erected in a body of water,said means including an air supply chamber disposed at one end of saidtubular casing and in fluid communication with downstream ends of saidtubular passages, said air supply chamber being divided into a first airreceiving space and a second air receiving space, said first airreceiving space being in fluid communication with said tubular passagesand with said tubular passages and with said second air receiving space,said second air receiving space adapted to receive air from an externalair supply source and having an opening for fluid communication with abody of water to be circulated, said first and second air receivingspaces being separated by a first partition wall in said air supplychamber and being in fluid communication with each other by means of atleast one aperture in said first partition wall, said aperture in saidfirst partition wall being closer to said downstream ends of saidtubular passages than said opening communicating said second airreceiving space with the body of water to be circulated and said firstair receiving space being separated from said tubular casing by means ofa second partition wall in said air supply chamber; whereby air suppliedto said second air receiving space intermittently accumulates in saidfirst and second air receiving spaces until an air mass having apredetermined volume is formed, at which point the air mass is in fluidcommunication with said tubular passages and passes through said tubularpassages in a bullet shape to effect a lifting action on water above theair mass and a suction action on water located below the air mass topump up water through said tubular passages.
 2. The water circulationapparatus of claim 1, wherein said first air receiving space is in fluidcommunication with said tubular passages by means of at least oneaperture in said second partition wall, said aperture in said secondpartition wall being further from said downstream ends of said tubularpassages then said aperture in said first partition wall.
 3. The watercirculation apparatus of claim 2, wherein said opening communicatingsaid second air receiving space with the body of water to be circulatedis spaced further from said opening in said first partition wall thansaid aperture in said second partition wall is spaced from said openingin said first partition wall.
 4. A water circulation apparatuscomprising:a tubular casing having a plurality of tubular passages, eachof which having an inlet at a downstream end thereof for receiving airand water and an outlet at an upstream end thereof for discharging airand water therefrom, said plurality of tubular passages extending alongthe entire length of said tubular casing; and means for intermittentlypassing large air masses through said tubular passages, said meansincluding an air supply chamber disposed in fluid communication witheach of said tubular passages, said air supply chamber including an airsupply compartment in fluid communication with each of said tubularpassages, said air supply compartment having an air inlet port forreceiving pressurized air, said air supply compartment having at leastone first air receiving space and means for intermittently dischargingair from said first air receiving space to said plurality of tubularpassages after a predetermined volume of air supplied continuouslythrough said air inlet port is filled into said first air receivingspace, said air supply chamber including a jacket to define an outerwall of said air supply compartment, said air supply compartment havinga first partition wall therein defining said at least one first airreceiving space, said means for intermittently discharging aircomprising a second partition wall disposed inwardly of said firstpartition wall to define at least one second air receiving space, saidfirst partition wall having an opening therethrough and said secondpartition wall having an opening therethrough which is spaced furtherfrom an upstream end of a respective one of said tubular passages thansaid opening in said first partition wall, said means for intermittentlydischarging air further comprising an opening in said jacket into saidfirst air receiving space for fluid communication with a body of waterto be circulated, said opening being spaced further from an upstream endof a respective one of said tubular passages than said opening in saidfirst partition wall, whereby air admitted into said air inlet collectsin said first and second air receiving spaces until the volume of airreaches said opening in said second partition wall, at which point alarge air mass passes by a siphon effect into each of said tubularpassages; whereby an intermittent large bullet shaped air mass passesinto each of said plurality of tubular passages to effect a liftingaction on water above the air mass and a suction action on water belowthe air mass to pump water through said plurality of tubular passageswhen said water circulation apparatus is erected in a body of water andpressurized air is supplied continuously to said air inlet port to fillsaid first air receiving space with a predetermined volume of air whichis periodically discharged.
 5. The water circulation apparatus of claim4, wherein, a plurality of first air receiving spaces are provided, eachof which is in fluid communication with a respective one of saidplurality of tubular passages.
 6. The water circulation apparatus ofclaim 5, wherein said jacket is spaced concentrically around an outerperipheral wall of said tubular casing and a top end plate extendsradially inwardly form said jacket at a position between said opening insaid first partition wall and said upstream end of a respective one ofsaid tubular passages, said first partition wall being spaced radiallyinwardly of said jacket and said second partition wall being spacedradially inwardly of said first partition wall.
 7. The water circulationapparatus of claim 4, wherein a single first air receiving space isprovided which is in fluid communication with all of said tubularpassages.
 8. The water circulation apparatus of claim 7, wherein saidjacket is spaced concentrically around an outer peripheral wall of saidtubular casing and a top end plate extends radially inwardly from saidjacket at a position between said opening in said first partition walland said upstream end of a respective one of said tubular passages, saidfirst partition wall being spaced radially inwardly of said jacket, saidsecond partition wall being spaced radially inwardly of said firstpartition wall, and a plurality of openings are provided in said secondpartition wall for passage of a large air mass into each of said tubularpassages.
 9. The water circulation apparatus of claim 7, wherein saidjacket extends axially from a downstream end wall of said tubularcasing, said first partition wall being spaced radially inwardly of saidjacket and said second partition wall comprising a tubular conduitspaced radially inwardly of said first partition wall, said tubularconduit extending through said end wall of said tubular casing forpassage of intermittent large air masses from said air supplycompartment into each of said tubular passages.